Phylogenic Characteristics of a Unique Antagonistic Micromonospora Sp. Rc5 to S. aureus Isolated from Sinai Desert of Egypt

A distinct strain named Micromonospora sp. Rc5 was isolated from Sinai desert of Egypt and recorded high antagonistic activities against some food and bloodborne pathogens. Morphological and chemotaxonomy characterization confirmed that this isolate belongs to genus Micromonospora. Sequencing of partial 16S rDNA and BLASTN showed that isolate Rc5 is identical to Micromonospora haikouensis (99%) but with low bootstrap value in NJ phylogenetic tree. Comprehensive optimization of several growth factors was performed including initial pH, incubation periods, and different sources of carbon and nitrogen. The highest yield of antimicrobial agent production was obtained after 8 days of incubation at 30°C, pH 6.0, 3 x 105CFU/ml in soya bean meal broth media with agitation of 150 rpm. A dramatic proportional decrease occurred with 0.3, 0.6, 0.9 µg active fraction /ml against Staphylococcus aureus culture and reached to complete inhibition at a minimum inhibitory concentration of (1.5 µg /ml). The physicochemical characterization of the purified fraction was identified as phthalate derivative. Our results indicated that Rc5 generated potential antimicrobial compounds against foodborne pathogens and   may combat resistant strains of Staphylococcus aureus.

Micromonospora is a normal occupant of actinorhizal nodules.

Actinorhizal plants have been found in eight genera belonging to three orders (Fagales, Rosales and Cucurbitales). These all bear root nodules inhabited by bacteria identified as the nitrogen-fixing actinobacterium Frankia. These nodules all have a peripheral cortex with enlarged cells filled with Frankia hyphae and vesicles. Isolation in pure culture has been notoriously difficult, due in a large part to the growth of fast-growing contaminants where, it was later found, Frankia was slow-growing. Many of these contaminants, which were later found to be Micromonospora, were obtained from Casuarina and Coriaria. Our study was aimed at determining if Micromonospora were also present in other actinorhizal plants. Nodules from Alnus glutinosa, Alnus viridis, Coriaria myrtifolia, Elaeagnus x ebbingei, Hippophae rhamnoides, Myrica gale and Morella pensylvanica were tested and were all found to contain Micromonospora isolates. These were found to belong to mainly three species: Micromonospora lupini, Micromonospora coriariae and Micromonospora saelicesensis. Micromonospora isolates were found to inhibit some Frankia strains and to be innocuous to other strains.

Isolation and Purification of Antibiotic from the Fermentation Broth of Micromonospora carbonacea JXNU-1 and Its Physical-chemical Properties / 微生物学通报

Based on the strain of Micromonospora carbonacea JXNU-1 with board-spectrum antimicrobial activity, the technology for the isolation and purification of antibiotic from the fermentation broth of the Micromonospora carbonacea, and its physical-chemical properties were studied. The results showed that, the antibiotic was stable under the condition of high temperature and alkali, but not in acid solution. After the pretreatment of centrifugation and filtration to remove the cells and lipids, the antibiotic was absorbed to negative exchange resin, and the impurity was excluded when 2 mol/L NaCl was used as primary eluent. The antibiotic could be eluted with 20% alcohol as eluent, and the eluting speed of the antibiotic was greatly accelerated as 2 mol/L NaCl was added into 20% alcohol as final eluent. Aqueous solution of the antibiotic was yielded from the alcohol-salt eluant by decompression concentration to wipe off alcohol and by dialysis to exclude salt. One active component was detected in antibiotic solution by paper chromatography, and theHPLC purity was over 99%. As the antibiotic shows positive color-forming reaction to Molish reagents, Benedict’s reagents and Diohenvlamine reagents, combined with the characteristics of absorption spectra, it is deduced that the antibiotic belongs to nucleoside antibiotics.

Daidzein and Genistein produced by a marine Micromonospora carbonacea FIM 02-635 / 中国海洋药物

Objective To study the active secondary metabolites from marine microorganism FIM02-635. Methods The producing strain was identified by taxonomical and phylogenetic studies. Two compounds FW635I1 and FW635I2 with immunosuppressive activities were extracted by organic solvents from the culture broth and purified by silica gel column chromatography and high speed counter current chromatography. The structures of the two compounds were determined by physico-chemical properties and spectral analyses,the biological activities were assayed in vitro. Results and Conclusion The producing strain was named as Micromonospora carbonacea FIM 02-635. Two compounds FW635I1 and FW635I2 were determined to be isoflavone Daidzein and Genistein, respectively, showed immunosuppressive and antitumor activities, but not antimicrobial activities.

Study on the High Yield Strain of Gentamicin Producer by Protoplast Fused and Fermentor Test / 中国生物工程杂志

The protoplasts of Micromonospora purpurea,the high yield strains of gentammicin producer were mutagenized by diethyl sulfate(DES)and ultraviolet radiation(UV)respectively,then fused,screened by gentamicin resistance and regenerated.The average fermentation unit 2200?U/ml could be achieved by shake flask for 10 batches.The average fermentation unit 1900?U/ml could be obtained by 5L fermentor for 7 batches.The quality of the end product conformed to CP2000,BP2000 and USP26 pharmacopoeia.

Isolation,purification and structure determination of antifungal antibiotic FW03-1149 produced by marine Micromonospora sp.FIM03-1149 / 中国海洋药物

Objective To study the antifungal metabolites from marine microorganism FIM03-1149.Methods The producing strain was identified by taxonomical studies.The antifungal compound FW03-1149 was extracted by organic solvents and purified by silica gel column and preparative HPLC from the culture broth of FIM 03-1149.The structure of FW03-1149 was determined by MS data analysis and physico-chemical properties.Results and Conclusion The producing strain was named as Micromonospora sp.FIM03-1149.Compound FW03-1149 was determined to be neorustmicin,showed strong antifungal activities.

Daidzein and Genistein produced by a marine Micromonospora carbonacea FIM02-635 / 中国海洋药物

Objective To study the active secondary metabolites from marine microorganism FIM02-635.Methods The producing strain was identified by taxonomical and phylogenetic studies.Two compounds FW635I1 and FW635I2 with immunosuppressive activities were extracted by organic solvents from the culture broth and purified by silica gel column chromatography and high speed counter current chromatography.The structures of the two compounds were determined by physico-chemical properties and spectral analyses,the biological activities were assayed in vitro.Results and Conclusion The producing strain was named as Micromonospora carbonacea FIM 02-635. Two compounds FW635I1 and FW635I2 were determined to be isoflavone Daidzein and Genistein,respectively,showed immunosuppressive and antitumor activities,but not antimicrobial activities.

Isolation and structure identification of bioactive fraction AM105-Ⅱ from marine actinomycete / 中国海洋药物

Objective To isolate and identify the anti-MRSA bioactive fraction from the fermentation broth of the marine-derived actinomycete AM105.Methods By means of silica gel column chromatography,preparative TLC and Sephadex LH20 column chromatography,the bioactive component was purified.The structure was determined by the spectral methods.Results and Conclusion The bioactive component AM105-Ⅱ was purified and the spectra showed that AM105-Ⅱ was composed of rifamycin S and its isomer,named isorifamycin S,which is a novel structure compound.Its antibacterial activity is better than rifamycin SV according to MIC.

Isolation and Identification on One Marine Actinomycete Strain with Antitumor Activity / 微生物学通报

One marine actinomycete strain FIM02-523 was isolated from marine soil in the East China Sea in Fujian Province. The fermentation broth of strain FIM02-523 exhibited potent antitumor activities. Strain FIM02-523 grew well on most media tested, the colonies were orange to dark brown but lacked aerial hy-phae, no diffusible pigments were observed. Phylogenetic, chemotaxonomic, morphological analyses, physiological and biochemical characteristics demonstrated that strain FIM02-523 belong to the genus Mi-cromonospora, may be a strain of the type species Micromonospora chalcea.

Isolation and Identification of a Strain of Micromonosporawith Broad-spectrum Antimicrobial Activity / 微生物学通报

A rare strain of actinomycetes, with broad-spectrum antimicrobial activity, was isolated from the soil samples from the farmland in the area of Yaohu lake in Nanchang. The information about the taxonomic identification, such as the morphology, physiological properties, cell components and 16S rRNA gene se-quences, suggested that the rare strain of actinomycetes was identified as Micromonospora carbonacea.

Taxonomy and Application of Micromonospora / 微生物学通报

Micromonospora distributes extensively in environment. But most of them have not been known because the limitation of isolation and taxonomic approach. The phenotypic information such as morphological, cultural and physiological characteristics have been applied widely in the taxonomy of Micromonospora. The functions of molecular methods become more and more important in the taxonomy of Micromonospra accompanying with the development of the polyphasic taxonomy. Micromonospora is one of the most important sources in finding new bioactive compounds, some of them can yield antibiotics, such as gentamicins, rafomicins and newmicins, some of them can degrade natural rubber and fibrin. It indicated in recent years’ study that some bioactive compounds with particular chemical construction could be found from Micromonospora. These compounds can identify cancer cells and kill them effectively.